Vehicle tire scuff detector



Dec- 65 1932 J. F. pusy 1,890,218

' VEHICLE: TIRE ScUFF DETECTOR Filled Notas. 1931 4 sheets-sheet 1l YDec. 6, 1932. u. E. DUBY 1,890,218

VEHICLE TIRE ASGUFF DETECTOR Filed Now/.25, 1931 4 sheets-sheet 2 Dec.6, 1932. J. F. DUBY VEHICLE TIRE SCUFF DETECTOR Filed N0v.25. 1931 4Sheets-Sheet 3v J. F. DUBY VEHICLE TIRE scUEF DETECTOR 4 Sheets-Sheet 4Filed N0v..23. 1931 J5 van? to the fact that the tire resumesnormalcyPatented 6, 1932 l* y UNI-TED STATES PATENT OFFICE JOHN FABIEN DUBY, l'BOSTON, HASBACBUBETTS vaincra rma soun' nnrnc'ron Application nledNovember 83, 1081. Serial lo. 576.756.

to bring about any agreement as to what the relative positions of a pairof wheels should be in regard to the three major items, viz, camber,caster and toe-in. Automotive engineers still diter in their opinions asto the best settings of these three items.

Under present day conditions there is no established degree of angularrelationship between the wheels. Therefore, I completely ignore suchrelationship and test the action of a tire while in actual contact withthe road.

Tire wear caused byscutling, may result from either camber, caster,toe-in, or from a combination of two or more of these items. It may be afore and aft scu, due to the smaller diameters at the sides of the treadbeing dragged along by the larger diameters at the center of the tread,or it may be a lateral seuil. This lateral yscui may be in voppositedirections, at the same time, at different points throughout the area ofcontact with the road. For example: when there is a combination ofcamber and toe-in there may be a lateral distortion of the tire in onedirection at one point, dueto camber, and a lateral distortionin theopposite direction-at another point. due to toe-in. The lateraldistortion caused by camber may be of such a nature that it will notcause any lateral scufling, due

" J' before it reaches a point where scuing would take place. In thisway there may be a distortional force in one direction, which is notharmful, and a scuing action of equal force in the opposite direction.vThese forces may he of such anature that when wheels are` tested on theplatform type of gage the scu ing action in one direction will be offsetby the distortional force in the opposite direction, thereby resultingin no movement of the indicator althoughscumg is actually taking place;also certain tire distortions will cause the platform to move andindicate im roper angular relationshi `of the wheels, w en as a matterof fact, t ere is no actual scuiing acton taking place.

Elimination of any scuin action is the only practical way to avoiexcessive tire wear and t0 obtain perfect steering conditions, y

and it is more practical to apply the test directly to the primary causeof tire wear in each case.

In order to accomplish the above results l provide a structure wherebythe tire may be tested under actual road conditions with the wheelsalways remaining substantially engaged with a fixed su porting surfaceduring the test. Any lateralscuing in either direction that may takeplace at any point throughout the area of contact will be shown by theindicator regardless of any opposing forces that may be present at otherpoints.

My device is adapted primarily to detect any lateral scuiiing actionwhich may take place at an point throughout the area of contact. T ewheels may then be adjusted to eliminate the scui ina thoroughlysatisfactory manner, without any attempt to measure or make specialallowances for the various angles involved.

In the accompanying drawings:

Fig. 1 is a plan view of the improved apparatus, various positions ofthe wheels being diagrammatically indicated;

Fig. 2 is a front elevational view of my improved indication device;

Fig. 3 is a plan view substantially at the center ofthe apparatus, withcover plates removed;

Fi g. 4 is a plan view of one end of the ap aratus, on an enlargedscale, certain parts eing removed for clearness; y

Fig. 5 is a view, partly in' section and partly in end elevation, of aportion of the supportpg means for one of the depressible elemen y Fig.6 is a side elevation of a portion of the assembly shown in Fig. 5.

Fig. 7 is a section indicated by line 7--7 of Fig. 4, showing thearrangement of the trip mechanism: y Y

* yand first more particularly to depressible element as the wheelpasses over the saine.

8 and 9 are sections indicated by lines '8-8 and.9'9 respectively ofFig. 4.

Fig'. 10 is a section indicated by line 10-10 of Fig. 2 ;l l f Fig'. 11is a detail view, partlyin elevation and partly in section, of a portionof the standard shown in Fig. 2;

Figs. 12 and 13 are views of portions of the trip mechanism, showing thesame in diiiferent positions; and' VFi s. 14, 15 and 16 are diagrammaticviews showing the relative positions of a wheel and Referring totheaccompanying drawings, igs. 1 and 2, it will .be seen that my improvedapparatus may :comprise a pair of transversely. disposedl de- Ipressible bars or elements 1, which may be provided with suitable tirecontacting sur-V aces adapted to insure positive engagement with a givenportion of .a vehicle tire.

protrude vfrom slots 2 formed in fixed wheel i' These dcpressiblelelements may normally supporting members 4 and 5` and adapted to beengaged by wheels on oppositey ends of a vehicle axle tree.

A suitable transverse'casing7 is dispod between the adjoining ends'ofthe elements 1 36# andA contains connecting linkage ywhichv willpresently .be'describetL Removable covers 9 l are disposed at the remoteends of the element 1 and' are designed to protectand concealadditionalportionsof the operating mechanism.

:At one' end of the apparatus, for example, at v the left as seen inFigs. 1 and 2, isan u stand- -ing post or standard 12 with a rotatab eindicater-element 13 at its top provided with-a depending pointer 14whichmay'move past a plurality of graduations disposed near the y of the.post 12.

eferrmg to Figs. 8 to 6 inclusive, each ofl I vthe elements 1 has itsrespective ends secured bvy screw bolts 15'to supportingv plates 16.lates 16 are mounted upon rollers 17 which arelrotatable'about axles 18,the latter carrying lrectangular guide blocks at their ends which arevertically slidable in slots in u G neat'h the transverse cover plate 7.Figs. 1 and 3. The springs 23 may have adjoining ends connected by hooksto a centralangle mem- Aes 4her 27 and maybe connected to links 28 whichengage the'dep'ending arms 24 upon the inner or achoining shafts 22. Thespring 23 should lhavey a' tension suliicient to insure-a non-slip-`enga ment the bars-1 and vel ing hielo tires ut this tension should notbe great enough to cause the harto materially i .I ish the normalfrictional engagement between the tire and its supporti sur ace. Linksnik connect the arms 24 of t e inner shafts be- It is thus evident thata vertical force tendl i in to press the bar 1 downwardly will be eective in pullingthe plates 16 at the ends of that bar and the rollers17 downward, therei by rocking the shafts 22, swinging the dependingarms 24 and thereb stressing the corresponding spring 23. en such n.

downwardly acting force is removed `from' the element 1, the springs 23will swing the arms 24 and move the rollers 17 upwardly to return theplates 16 and element 1 to their original position asshown in Fig. 6. Itis 'evident that this downwardA and upward movement of the elemental mayoccur independently of any longitudinal 4movement, thereof which in turnmay take place inde-v Eendentl of Lany verticalmovement of the ar by patea 16,cooperating with rollers 17. The fixed cross members Fig. 3, areadapted to kengage bars 1 to limit their upwardtravel and the frictionalengagem nt therebetween also prevents over-trave of the bar has beenbroken.

g Element 1, which is remote from the indicator, hu a vertical pn whichis slidably received lin an opening` in the odset end of link 187,' thelatter sliding in a guide 89. The other element 1 `has a vertical in 43fixed in its end and slidably reeeiv in an opngig inan operating link44, (Figs. 4 .n l l As shown in Figs. 4 and 10, operating links 42 and44 are disposed in paral elism and extend beneath the lower end of thehollow standard'12. Thess links are ivotally counected to a transversecrank ar 46 which is fixed .to the lower end ot a rod 47 de nding fromthe center of the rotating in icuting plate`18. Referring to Fig. 11, atthe upper end otrod 47, I provide a inter carrying disc 47, the latterbeing xsd to said rod. A hub on the disc engages the upper surface ot asupporting elemen' 14l suits ly attachedI to the inner wall of standard12.

An aperture in element 14* which is slightly greater in diameter thanrod47 rmits movementof the lower end ofthe ro in any horizontal direction.

If bothbars move the same amount, in the bar after contact between thetire and the ics same direction, there would be a resulting swingingmovement of the rod 47 but no rotary` movement thereof.- If one of thebars nieves' longitudinally therev will be' a correspending movement ofits respective end of ant rotarymovement of the rod 47 and pointer 14will indicate the total amount of longitudinal movement of both barswith respect to each other. Inaddition to pointer 13, I have provided anindependent fixed gage block having marker points thereon, which incooperation with marker points on the links 42 and 44, indicate theactual amount of longitudinal movement of each bar with respect to afixed point and may be read through aperture 45, Fig. l.

The bars 42 and 44 carry upstanding pins and 51 which are received insuitable i'nterconnected slots in a sliding plate 53. As shown in Figs.12 and 13, the plate 53 has a slot portion '56 with parallel sidesspaced to receive the pin 50 and this slot merges into a recess 57 u'ith diverging sides and of generally' triangular formation; the baseportion'of the triangular recess is connected to a second parallelWalled slot portion 56, which in turn is connected to a triangularenlargement 57 a. The slot portions 56 and aperture 57 receive the pinl50, whilecorresponding portions 56a and 57l receive the pin 51. Theplate 5? is held in place by clips 60, (Figs. 4 and 7) so that it mayslide'longitudinallv, and its ends are provided with pivot pins 61engaging slots'in levers 62, one of these levers normally beinginoperative but being provided so that the trip mechanism may bearranged adjoining either side of the platform member 4.l As shown, theends of levers 62 are mounted upon fixed pivots G3 and one of theselevers is engageable with a stop stud 64, a spring 65 normally7 tendingto press this lever against the stop stud. A link 66 may connect eitherof these levers 62 to a crank 68 depending from the swinging trip memberwhich may be placed 1n a Wheel engaging position at either edge ofiember 4. as desired. The body portion of this member consists of asubstantially U- shaped bar and is provided with projecting end portionsto be received in bearings 71, one end of the bar being bent. down toprovide' the crank 68, as shown in Fig. 7, while the other end of thebar is correspondingly bent to provide a crank 68a when bar 70 is usedon the opposite side of member 4. Ordinarily. member 70 is disposed inadvance of the Wheel supporting surface as shown in Figs. 1 and 7. sothat it is readily engageable by the wheel of a vehicle when driven ontothe surface, whereupon the trip member 70 wvill be depressed to theposition indicated by dot anddash lines in Fig. 7, thus swinging atinglinks 42 and 44 are returned to a position which will cause the crankblock 46 to be disposed as shown in Figs. 10 and 18 and consequently thepointers to a zero position.

As soon as the vehicle Wheels move out of engagement with the member70,v the spring (i5 is effective in returning the lever 62 to its normalposition. thus swinging the crank 68 and the member 70 to the full lineposition of Fig. 6 and also moving the plate 53 to a position whereinthe enlarged aperture portions 57 and 57 receive the pins 50 and 51 sothat the pins may move transversely of the plate 53 as shown in Figs. 4and 12.

It Will be evident from the above that the elem-ents 1. are positivelyplaced in operating position above the Wheel supporting surface, thepointer 14 set at zero, and the marker points on links 42 and 44 broughtto registering position with marker point on block 45, just efore theelements are engaged by a pair of Wheels to be tested. Therefore, nointervening cause can interfere with a correct setting for the test.

In the operation of apparatus of the characterdescribed, a vehicle isdriven toward the apparatus so that the wheels on an axle tree, as forexample the front wheels, after passing over member 70, which brings thepointers to a zero position, may engage the depressible bars 1. Forexample, the Wheels indicated in dot and dash positions of Fig. 1 areshown in this contacting position. Figs. 14, 15 and 16, illustrate themovement of a vehicle wheel as it rolls over element 1. It may beassumed that the vehicle and its axle are moving in the directionindicated by the horizontal arrows, the tire rolling rtoward the bar 1in Fig. 14 until the point upon its periphery contacts therewith and theWheel is in position C. This point A remains in contact with the bar asthe Wheel rolls into and through mid-position M, Fig. 15, and then on toposition L, shown in Fig. 16. The tire being about to leave the bar 1which has returned toits uppermost position. Throughout the positions C,M, and L during the period of contact between the bar 1 and a peripheralportion of the tire, there has been no relative movement therebetween.The bar l is movable both vertically and longitudim nally with the tireduring the period of contact; consequently any movement of the elementas the tire moves through these positions affords an accurate indicationof scuing action between the tire and. the road surface.

Obviously, when two such tire engaging elements are ein loyed withllinkage of the l l. i

lili.

moyement of the bars if there is a scuing action taking place. In otherwords, assuming the movement of each bar 1- m a horizontal directionaway from the other to be positive, the indicator will show a continuousinstantaneous indication ofthe algebraic sum of the longitudinalmovement of both bars throughout the period of Contact.

It is evident that my invention provides a device wherein the wheelcontacting elements afford a reading which is dependent upon thelongitudinal movementof the elements 1 n when engaged with a portion ofthe tire lll) between the flattened portion thereof and the point oftire contact with bar l is governed jby the normal height of the barabove the tire supporting'surface. A reading may be obtained without anyvertical movement of the bar; however, I have found that with presentday tires, a vertical movement of approximately 1/1 inch is moresatisfactory, as it will allow the tireto sufficiently resume its normalshape to give an accurate reading, including vany distortion which mayexistv at the point where the tire breaks contact with the road.

It is evident that other forms of bars or blades may be used providedtheir proportions and arrangements are such as not to materiallydiminish the normal area of contact or frictional engagement between thetire and its fixed supporting surface.

It will be clear that my device will give an accurate reading if theelement 1 1s adapted to engage with only one of a pair of wheels,

` becauseof the fact that the tires are always inrontact with a fixedsupporting surface with reference to lateral movement; therefore theelement l is responsive only to lateral movement of that tire with whichit is engaged. Obviously, it is more convenient and time-saving to testboth wheels at once.

It should be understood that the present disclosure is for the purposeof illustration only and that thisv invention includes all modificationsand equivalents of a substantially narrow wheel engaging elementcooperating with a fixed wheel supporting surface substantially for thepurpose set forth herein.

vlll/That I claim is:

l. Apparatus of the class described com- `prising means presenting atleast one fixed wheel-supporting surface, a gaging element associatedtherewith for the purpose set forth, a tire contacting region on saidelement, said region being movable in a direction lateral tothe path ofa wheel traversing the supporting surface and element, the width of saidregion, inthe direction of wheel travel, being of a small dimension incontrast with the length of the area of usual tire and road engagement,whereby the presence of the gaging element will cause only a negligiblevariation from ordinary tire and road contact conditions while a wheelis traversing said surface. v

2. Apparatus of the class described comprising a portable unitpresenting a fixed wheel-supporting surface, a movable gaging elementassociated therewith for the purpose set forth, means to indicate themovement of said element, a tire contacting region on said elementengageable by a tire and movable in a direction lateral to the path of awheel traversing the supporting surface and element, the width of saidregion, in the direction of wheel travel, being sufficiently less thanthe length of usual tire engagement with a road for its presence tocause only a negligible variation from normal tire and road contactconditions as a wheel `traverses said surface, and means to reset theelement-to zero position.

3. Apparatus of the class described comprising means presenting a fixedwheel-supporting surface, a gaging element associated therewith for thepurpose set forth, a tire engaging portion on said element, said portionbeing movable by a tire in a direction lateral to the path of a wheeltraversing the supporting surface and element, the width of said portionin the direction of wheel travel being of a small dimension in contrastwith the length of usual tire engagement with a road surface, and meansassociated with the tireengaging portion of the element to indicate anylateral movement of said portion.

4. Apparatus of the class described comprising means presenting a fixedwheel-supporting surface, a movable gaging element associated therewithfor the purpose set forth, a tire engaging region on said element, saidregion being movable by a tire in a direction ateral to the path of awheel traversing the supporting surface and element, the width of saidregion in the direction of Wheel travel being of a small dimension incontrast with the length of usual tire engagement with a road surface,means to indicate any lateral movement of said gaging element, and meansmovement of a wheel tire laterally to its path lill) of travel andrelative to said surface, said element being depressible when traversedby wheel, means yieldably supporting said element above said surface,the exposed reon of said element being of small proportions in thedirection of wheel travel so as to leave a substantial amount of thetire in engagement with the fixed supporting surface during thetraversing operation, and means to indicate any lateral movement of saideiemeut. i

G utpparatus of the class described comprising means'presenting a fixedWheel-supporting surface, a n'iovable gaging element associatedtherewith 'for the purpose set "toi-th, a tire engaging regimi on saidelement being movable'in a direction lateral to the path of a Wheeltraversing the supporting surface and element, the Width of said region,in the direction of wheel travel, being of a small dimension in contrastwith the length of usual tire engagement with a road surface, saidelement being normally positioned above said supporting surface, andyieldable supporting means for said element vvhereby it .may bedepressed When traversed by a vehicle Wheel.

7. The method of detecting undesirable movements bet-Ween a vehicle tireand the road in a direction lateral to the path of vehicle travel, whichconsists of. moving the vehicle forward while maintaining approximatelythe normal degree of frictional engagement between the tires and a fixedsupporting surface, providing a laterally displaceable elementassociated with said surface and utilizing any such movement of the tireto actuate said element.

8. The method of detecting undesirable movement between a vehicle tireand the road, which consists of rotating a pair of Wheels on their axes,thereby causing a given portion on the tire periphery to roll into andout of contact with a wheel supporting surface which is not movable inresponse to the lateral thrust of a tire, providing a laterallydisplaceable element to contact With said portion and measuring anymovement of said element in a direction lateral to the Wheel plane andrelative to said surface during such Wheel rotation.

9. The method of eliminating undesirable movements of a vehicle tirerelative to a road surface, which consists of providing an elementassociated with a fixed Wheel-supporting surface and operable inresponse to lateral movement of the tire, moving the vehicle forwardcausing a pair of Wheels to roll along said i'ixed supporting surfaceWhile maintaining substantially the normal degree of frictionalengagement therewith until a given point on the tire periphery rollsinto and out of Contact with said element, gaging the amount of lateralmovement of the element and subsequently making necessary adjustments ofvehicle parts to prevent tire scuiin 10. pparatus of the class describedcon1- prising means presenting fixed supporting surfaces for a pair ofWheels, a gaging element associated with each supporting surface, saidelement being movable laterally to a wheel plane in response to tirescufling action, vertically yieldable supporting means for saidelements, a tire contacting region on each of said elements, the Widthof said region in the direction of wheel travel being proportionatelynarrow in contrast with the length of usual tire engagement With a roadsurface, means to indicate the amount of transverse movement of thegaging elements, and means to return said elements to the zeroindicating position.

l1. Apparatus of the class described comprising means presenting yfixedsupporting surfaces for a pair of Wheels, a gaging element associatedwith each supporting surface, each element being independently movablelaterally to a Wheel plane in response to tire scuiing action, a tirecontacting region on each of said elements, the width of said region inthe direction of Wheel travel being of a. small dimension in contrastwith the length of usual tire engagement with a road surface, anindicator to show the net relative movement of the gaging elements, andmeans for utilizing the independent transverse movement of each gagingelement to actuate said indicator.

12. Apparatus of the class described comprising means presenting iixedsupporting surfaces for a pair ot Wheels, a gag-ing ele ment associate(with each supporting surface, said element being movable laterally to aWheel plane in response to tire scuiiing action, a tire contactingregion on each of said elements, the Width of said region in thedirection of wheel travel being of a small dimension in contrast withthe length of usual l tire engagement with a road surface, an inildicator, means connecting the indicator to each gaging element, andmeans to reset the elements to a zero indicating position.

13. Apparatus of the class described comprising means presenting fixedsupporting surfaces for a air of wheels, a gaging element associated)with each supporting surface, said element being movable laterally to aWheel plane in response to tire scuing ac tion, a tire contacting regionon each of said elements, the Width of said region in the direction ofWheel travel being of a small dimension in contrast with the length ofusual tire engagement with a road surface, an indicator, meansconnecting each element to the m5 indicator, and means to preventover-travel of the elements and retain the indication.

14. Apparatus of the class described comprising means presenting ixedsupporting i ice surfaces for a pair of wheels, a gaging eies@ mentassociated with each supporting surlface, said element being movablelaterally to a wheel plane in response to tire scutling action, a tirecontacting region on each of said elements, the width of said region inthe direction of wheel travel being of asluall dimension in contrastwith the length of usual tire engagement with a road surface, and meansto prevent over-travel of the gaging cien'ients.

l5. A\pparatus of the class described, comprising a pair of wheelsupporting surfaces, a pair or" spaced tire contacting elements,supporting means for the latter normally fielding the elements above thesupporting surfaces, means provided for longitudinal inovement ot theelements independently of perpendicular movement, a pair of linksconnected to the respective elements, a standard at one side of theelements, an indicator supported by the standard, i eans operablyconnecting the links with the indicator including a crank membercooperating with a pend ulousl y mounted rod, whereby the indicator iscaused to present a reading of the relative movement between theelements.

1G. Apparatus of the class described, comprising a pair of wheelsupporting surfaces, a'pair of spaced tire contacting elements,supporting means for the latter normally holding'the elements above thesupporting surfaces, means provided iio'r longitudinal movement of theelements independently of perpendicular movement, a pair of linksconnected to the respective elements, a standard at one side of theelements, an indicator supported by the standard, means operablyconnecting the links with the indicator including a crank membercooperating with a pendulously mounted rod, whereby the indicator causedto present a reading of the relative movement between the elements,friction means adapted to prevent over-travel after the elements havebroken contact with a pair or tires, trip mechanism operable bycontacting with a vehicle part, said last mentioned mechanism includinga movable plate having cam slots, whereby the links and associated partsmay be re-set to a zero indicating position. e

17. Apparatus of the class described comprising means presenting fixedsupporting surfaces for a pair of wheels, a gaging element associatedwith each supporting surtace, said element being movable laterally `to awheel plane in response to tire suling action, vertically yieldablesupporting means for said elements, means to yieldingly resist i'reedownward movement of said elements, an indicator and operableconnections therewith to show the relative lateral movement of theelements, and means to reset said elements to a zero position.

18. Apparatus of the class described comprising means presenting a`fixed Wheel-supporting surface, means movable laterally to a Wheel planeadapted for frictional contact with a tire periphery to detect certainsculing action between said surface and the tire as the latter traversessaid surface while in approximately full frictional contact with thefixed surface, means to indicate lateral movement of said detectingmeans, and operable connections Vbetween said indicating means and saiddetecting means.

19. Apparatus of the class` described comprising means 'presenting afixed Wheel-supporting surface for each of a pair of vehicle wheels, agaging element cooperating with each surface and being mounted forlateral movement in response to certain lateral tire scuiing action,said elements by nature of their proportions being adapted tofrictionally engage with a tire during atest without materiallydiminishing the normal degree oi' frictional engagement between the tireand its fixed supporting surface, each of said gan'- ing elements beingfree to move indepen ently of the other.

JOHN FABIENv DUBY.

